The new Sigma 17-70mm f/2.8-4 DC Macro HSM lens rumored to be released next month

The new Sigma 17-70mm f/2.8-4 DC Macro HSM lens (pictured on the left) is expected to be released in late January 2013 (probably during the CP+ show in Japan). The new lens will have an improved optical design and it will be 9mm shorter and 70g lighter then the current version (pictured on the right):